Boiler



Sept. 3o, 1930.

J. H. LAWRENCE ET AL 1,776,835

BOILER Filed June 18, 1925 2 sheets-sheet 2 imm jwuamtom Patented-Sept. 30, 1.9301y f UNITEDbsTA In a previous application'of Murray and Lawrence, No. 719,696 there is' described a boiler having a furnacel with one or more Walls of vertical Water tubesl with aspecial circulating system. The present invention is directed to certain improvements in such" a i tion illustrated, the furnace is enclosed .Within a front wall 1, offset from the boiler tubing', at the upper end of which is a horizontal Wall or arch 2- with openings through which pass.'

burners 3 `of the nozzle type for' projecting jets of powdered coal, oil or gas into the combustion chamber. AThese Walls; and the rear` Wall 4 and s ide Walls 5 ,(Fig. 2) are of 'any usual or suitable construction and material.

Above the combustion chamber vare' the usual' inclined, approximately horizontal,

boiler tubes 6 andthe superheater. tubes 7,

With baffles for directing the gases of combustion to heat the tubesby'convec'tion and to direct them out finallyby theA smokepipe 8 to the exhaust fan: or stack; these tubes beingy also enclosed in walls of any usual or suitable construction and materia l The approximatelyI horizontal tubes above the combustion chamber are supplemented by sets of vertical tubes 9 at the sides and si-milar tubes 10'at the VVrear of the combustion cham- -ber and exposed directly-tothe radiant heat of the burnin fuel; Preferably, as described in previous applications of Murray,

No. 67 8,443' and others, the tubes 9 and 10 i are of thekindillustrated in Fig. 3, with l'ongit-udinal finsV 11 welded thereto and overf through pipes 3 3 lconstituting a Water screen y for the' cinders ywhich fall from the co1nbus lapping each other so as to cover the spaces between thei tubes, to entirely shield the en` closing Walls of'masonry and to be exposed'to the heating gases on the inner rside onlyl of the Water Wall: These tins provide in effect `a greatly increased surface ofconducting ma- ",Appnqtion filed June Is,

TEsPATENr OFFICE j vANI) JAY AQEREIDAY, -OE-EAS'I' ORANGE METROPOLITAN ENGINEER- e -EOILER f '1925. serial No. '37,915.

terial exposed to the radiant heat of the furnace and transmitting such heat by conduction to the Watery Within the tubes, and thus greatly increase the etliciency ofthe boiler as a Whole.

rBecause ofthe high rate at Which the Water in these tubes is converted into steam, it is particularly important for el'liciency and also to prevent explosions,.that they be provided with a reliable circulating-system. The set of vertical tubes 9 at each side'of the furnace is connected With top andF bottom headers 12 and 13 respectively. The Waterv is supplied bto the bottom' headers as hereign after described and passes thence up through the vertical tubes, out through the top header discharging into vertical pipes 23 which enter the rear ends of the loWer headers 13 previously referred to.

` A separate circulation is provided for the tubes 1() of the rear Wall. The Water enters by way of the header 24 connected to their lower ends. Each of the tubes 10 at its upper end enters one of the vertical headers 25 at the ends of the horizontal tubes 6 which communicate by pipes 26 with similar headers 27 for the second bank of horizontal tubes,-

which' communicatejin turn With pipes 28,'

leading to the steam l,drum 17. The' Wat'er I passes out from the'drum 17 through down- Wardly inclinedpipes 29to loops 30 and thence by `vertical pipes .31 toa header 32 extending across the front of'the boiler. From the header 32 the water passes iirst tion chamber andbthence tov the `header 24 at the bottom of the rear Water Wall, The steam from -the drum passes out through pipes 34 to. thesuperheater tubes 17 5 provided as required.

2 i Y 1,776,83e

10' tubes provides a shorter andv easier path for the ascending Water and steam than Where a cross header is interposed, and thus secures an improved circulation. f

Theinvention is of particular importance in connection With the spaced flanged tubes f shown. With this construction the surface i exposed to the heat is so great in proportion to the size of the column of Water in the tubing that the latter is heated at a very much more rapid rate than in the ordinary design of boilers and it becomes ,more than ordinarily7 necessary to provide a free and easy circulation through these tubes.

Various modifications of the design and ar- \.25\rangement shown may be made by those skilled in the art Without departing from the invention as defined in the following claims.

What We claim is:

1. A boiler having a furnace with a plui ralityof Water Walls composed of vertical tubes exposed tothe radiant heat of the burning fuel and having horizontal tubes above the furnace heated by convection from the '35- furnace' gases, said tubes having inlet and -outlet headers andseparate circulating systemsfor said Mfaterwalls, one system including said inlet headers only and another in- "cluding said outlet headers only.

46 2. A boiler having a furnace with opposite side Walls of vertical Water tubes and an end Wall of vertical Water tubes, exposed to the radiant heat of theburning. fuel, and having horizontal tubes above the furnace heated by convection from the furnace gases, said tubes having inlet and out-let headers and separate circulating systems for said water walls, one system including said inlet headers only and another including said outlet headers only.

0 3. A boiler having a furnace in Which are, i

first, a set of Water tubes forming Water Walls exposed to the radiant heat of the burning fuel and, second, a set of Water tubes beyond ythe furnace heated by convection from the j furnace gases, said tubes havingI inlet and outlet headers and separate circulating sys- ,tems for said Water Walls, one system includ.-

ing saidfinlet headers only and another including saidoutlet headers only.

4. A boilerhavingfirst a set of Water tubes exposed to the radiant heat of the burning fuel, said tubes being spaced apart and provided With flanges inthe intervening spaces so as to generate steam at a high rate and to require a rapid circulation, and having, second, a set of tubes beyond the furnace heated by convection from the furnace gases, and having headers on the inlet and outlet ends of the second set of tubes, and separate circulating systems for different groups of the first set of tubes, one of said circulating systems including only the aforesaid inlet headers and the other including only the aforesaid .outlet headers.

5. A boiler having a furnace with a first set of Water'tubes exposed to the radiant heat of the burning fuel and a second set of Water tubes beyond the furnace heated by convection from the furnace gases, having headers on the inlet ends and the outlet ends of the second set of tubes and a first circulatingsystem including inlet headers, of the second set of Water tubes, a connection between such headers and the inlets of certain Water tubes of the first set and a direct connection from the outlets of the last named Water tubes to the steam drum, and a second circulating system including outlet headers of the second setl of Water tubes, a connection between such headers and the outlets of certain other water `tubes of the first set and a direct connection from the steam drum to the inlets of the last named Water tubes.

6. A boiler having a furnace with a rst set of Water tubes exposed to the radiant heat 9 of the burning fuel, a second" set of Water tubes beyond the furnace heated by convection from the furnace gases and inlet headers and outlet headers at the ends of said second set of tubes, said boiler including a steam drum and having two circulating systems, the first system leading from the drum through said inlet headers and outside of the furnace to the inlet ends o f certain of the first set of Water tubes and through such tubes to the drum and the second system leading from the drum to the inlets of certain others of the first set of water tubes and through such tubes to the outlet headers of the second set and thence to the drum.

In witness whereof, We have hereunto signed our names.

JOHN H. LAVRENCE.

JAY A.- FREIDAY. 

